This report includes the previously unpublished primary and derivative data sets that underpin the construction of the three dimensional (3D) geologic map of the upper part of the Earth's crust beneath the Sacramento-San Joaquin River Delta, California. The primary data is X,Y,Z locations of stratigraphic horizons and, to a much lesser extent, geologic structures where penetrated by oil and gas wells in the subsurface as recorded in well logs and well records. The derivative data sets were constructed to more closely constrain the principal stratigraphic horizons and geologic structures that were incorporated into the 3D model. The derivative data sets are extracted from the principal data set or a combination of the principal data set with other previously published data. This Data Release is not intended to be a stand-alone publication, but is only intended to release the digital data sets that undergird the related Scientific Investigations Report. The information in this Data Release mainly describes the details of the contents and formats of the digital files. The user is encouraged to refer to the main report for more discussion of sources and methods.

This report and associated dataset, contains subsurface geologic information collected in the Sacramento-San Joaquin Valley. The primary data includes X, Y, Z locations of stratigraphic horizons and, to a much lesser extent, geologic structures where penetrated by oil and gas wells in the subsurface as recorded in well logs and well records. Selected oil and gas wells are not only examined for depth to stratigraphic horizon data, but also marked if deviated from vertical, or containing specific electronic logs that may be used for geophysical research. The data was compiled from well records made available through the California Department of Conservation, Geologic Energy Management Division (CalGEM) Well Finder web interface. Well Finder provides a map view of wells and fields with links to well records in the CalGEM database. Select records for wells in the study area (principally the well data report, which is a PDF copy of all the forms and associated "paperwork" filed with CalGEM and its predecessor state agencies, and the standard Spontaneous-Potential/Resistivity/Conductivity electric log) were requested, downloaded, and examined. Measurements of depth to geologic features (horizons) such as top or bottom of a geologic unit that are recorded in the well records were compiled into the data set, along with information about the location and identity of the well, and whether the well records available include other types of well log that are commonly of interest to 3D mappers. We also recorded if the well record mentioned that the well is deviated (not entirely vertical), which would affect the true X,Y,Z location of recorded horizons. However, we did not attempt to correct the data to account for the deviation. The values in the data set are those recorded in the well records. We also harvested the same information from the previously published USGS Open-File Report 2011-1262 (Brabb, 2011). Where there are many wells close together, we examined well records until finding a well with a relatively large suite of horizon depths recorded, and then used that well as representative of the many closely spaced wells. The goal was to get a good representation of the regional subsurface, not to record every well. In addition, we did not record all the information available in the well records for those wells in this dataset. The full records are freely available from the data sources. This dataset includes specific information compiled for the purpose described below. The information in this metadata file mainly describes the details of the contents and formats of the digital files.

The U.S. Geological Survey acquired high-resolution P- and S-wave seismic data across the Frijoles Fault strand of the San Gregorio Fault Zone (SGFZ) at northern Año Nuevo, California in 2012. SGFZ is a right-lateral fault system that is mainly offshore, and prior studies provide highly variable slip estimates, which indicates uncertainty about the seismic hazard it poses. Therefore, the primary goal of the seismic survey was to better understand the structure and geometry of the onshore section of the Frijoles Fault strand of the SGFZ. We deployed 118 geophones (channels) at 5-m spacing along a linear profile centered on the mapped surface trace of the Frijoles Fault and co-located active P- and S-wave sources at ~1-m offset from the geophones. Channel numbers increase from west to east along the profile. We generated P-waves using either a seisgun (www.utep.edu/science/ssf/Manuals/betsy_seisgun.pdf, accessed August 2022) or an accelerated weight-drop and S-waves by horizontally striking an aluminum block on both sides with a sledgehammer. We first deployed vertical-component geophones (40-Hz, SercelTM L40A, sensitivity of 22.34 volts/meter/second) to record P-wave sources, after which we replaced the vertical-component geophones with horizontal-component geophones (4.5-Hz, SercelTM L28-LBH, sensitivity of 31.3 volts/meter/second) to record S-wave sources. Refraction cables connected all geophones to two 60-channel Geometrics Stratavisor NX-60TM seismographs with 24-bit analog-to-digital converters. Each shot was recorded at a 0.5-ms sampling rate for two seconds, with data recording at 100 ms before the actual time of the shot. This data release provides the metadata needed to utilize the seismic data. Data Format and Files We combined each seismic trace for a given shot time into a shot gather, and the traces in each shot gather are ordered by channel numbers (1-118) based on the position of the geophones along the profile. Furthermore, we assigned a unique field number (FFID) to each shot gather, and we combined the shot gathers recorded from both seismographs into two SEG-Y files (Barry et al., 1975), 78023.segy (channels 1 to 60) and marine.segy (channels 61 to 118), which are stored in big-Endian, 4-byte IBM-floating-point format (format code 1). Data samples are in millivolts and can be converted to velocity using the geophone sensitivity values. Metadata for all profiles are contained in two text files and one xml file: PIE12.setup.csv, PIE12.location.csv, and PIE12Metadata.xml. The setup file describes the identification of shots recorded by the two seismographs, channel number, recording stations (geophones), and the source type for both SEG-Y files. The location file describes the channel number, latitude, and longitude of all geophone locations. Reference Barry, K.M., Cavers, D.A., and Kneale, C.W., 1975, Recommended standards for digital tape formats: Geophysics, vol. 40, no. 2, p. 344-352, doi: 10.1190/1.1440530.

The U.S. Geological Survey acquired high-resolution P- and S-wave seismic data across the Frijoles Fault strand of the San Gregorio Fault Zone (SGFZ) at northern Año Nuevo, California in 2012. SGFZ is a right-lateral fault system that is mainly offshore, and prior studies provide highly variable slip estimates, which indicates uncertainty about the seismic hazard it poses. Therefore, the primary goal of the seismic survey was to better understand the structure and geometry of the onshore section of the Frijoles Fault strand of the SGFZ. We deployed 118 geophones (channels) at 5-m spacing along a linear profile centered on the mapped surface trace of the Frijoles Fault and co-located active P- and S-wave sources at ~1-m offset from the geophones. Channel numbers increase from west to east along the profile. We generated P-waves using either a seisgun (www.utep.edu/science/ssf/Manuals/betsy_seisgun.pdf, accessed August 2022) or an accelerated weight-drop and S-waves by horizontally striking an aluminum block on both sides with a sledgehammer. We first deployed vertical-component geophones (40-Hz, SercelTM L40A, sensitivity of 22.34 volts/meter/second) to record P-wave sources, after which we replaced the vertical-component geophones with horizontal-component geophones (4.5-Hz, SercelTM L28-LBH, sensitivity of 31.3 volts/meter/second) to record S-wave sources. Refraction cables connected all geophones to two 60-channel Geometrics Stratavisor NX-60TM seismographs with 24-bit analog-to-digital converters. Each shot was recorded at a 0.5-ms sampling rate for two seconds, with data recording at 100 ms before the actual time of the shot. This data release provides the metadata needed to utilize the seismic data. Data Format and Files We combined each seismic trace for a given shot time into a shot gather, and the traces in each shot gather are ordered by channel numbers (1-118) based on the position of the geophones along the profile. Furthermore, we assigned a unique field number (FFID) to each shot gather, and we combined the shot gathers recorded from both seismographs into two SEG-Y files (Barry et al., 1975), 78023.segy (channels 1 to 60) and marine.segy (channels 61 to 118), which are stored in big-Endian, 4-byte IBM-floating-point format (format code 1). Data samples are in millivolts and can be converted to velocity using the geophone sensitivity values. Metadata for all profiles are contained in two text files and one xml file: PIE12.setup.csv, PIE12.location.csv, and PIE12Metadata.xml. The setup file describes the identification of shots recorded by the two seismographs, channel number, recording stations (geophones), and the source type for both SEG-Y files. The location file describes the channel number, latitude, and longitude of all geophone locations. Reference Barry, K.M., Cavers, D.A., and Kneale, C.W., 1975, Recommended standards for digital tape formats: Geophysics, vol. 40, no. 2, p. 344-352, doi: 10.1190/1.1440530.

The U.S. Geological Survey acquired high-resolution P- and S-wave seismic data across the Frijoles Fault strand of the San Gregorio Fault Zone (SGFZ) at Año Nuevo, California in 2012. The SGFZ is a Holocene-active, dominantly right-lateral fault system that trends more than 200 km along the California coastline. The Frijoles Fault is one of several onshore strands of the SGF system, and together the strands represent a 3- to 4-km wide fault zone at Año Nuevo. Prior paleoseismology studies indicate highly variable slip-rate estimates, indicating considerable uncertainty about the slip history of the SGFZ and the seismic hazard it poses. Amongst the onshore strands of the SGFZ at Año Nuevo, the Frijoles Fault presented the fewest logistical challenges for our seismic survey; thus, the goal of this data acquisition was to better understand the structure, geometry, and precise location of the Frijoles Fault strand of the SGFZ at Año Nuevo.

The U.S. Geological Survey acquired high-resolution P- and S-wave seismic data across the Frijoles Fault strand of the San Gregorio Fault Zone (SGFZ) at Año Nuevo, California in 2012. The SGFZ is a Holocene-active, dominantly right-lateral fault system that trends more than 200 km along the California coastline. The Frijoles Fault is one of several onshore strands of the SGF system, and together the strands represent a 3- to 4-km wide fault zone at Año Nuevo. Prior paleoseismology studies indicate highly variable slip-rate estimates, indicating considerable uncertainty about the slip history of the SGFZ and the seismic hazard it poses. Amongst the onshore strands of the SGFZ at Año Nuevo, the Frijoles Fault presented the fewest logistical challenges for our seismic survey; thus, the goal of this data acquisition was to better understand the structure, geometry, and precise location of the Frijoles Fault strand of the SGFZ at Año Nuevo.

This report summarizes geomorphic data and analysis from the range front of the San Gabriel Mountains, California, USA. For catchment-average erosion rates, we describe the methodology used to collect samples of detrital sediment, determine concentrations of cosmogenic beryllium-10 in purified quartz isolated from the samples, and use those nuclide concentrations to calculate erosion rates. We also describe the methodology for calculating various topographic metrics from previously published lidar topographic data. These metrics include stream channel concavity, normalized channel steepness index, dimensionless hilltop erosion and dimensionless hilltop relief.

This report summarizes geomorphic data and analysis from the range front of the San Gabriel Mountains, California, USA. For catchment-average erosion rates, we describe the methodology used to collect samples of detrital sediment, determine concentrations of cosmogenic beryllium-10 in purified quartz isolated from the samples, and use those nuclide concentrations to calculate erosion rates. We also describe the methodology for calculating various topographic metrics from previously published lidar topographic data. These metrics include stream channel concavity, normalized channel steepness index, dimensionless hilltop erosion and dimensionless hilltop relief.

In June of 2011, the U.S. Geological Survey acquired high-resolution P- and S-wave seismic data across the mapped (Schussler, 1906) trace of the San Andreas Fault zone at San Andreas Lake in unincorporated San Mateo County, California. Our seismic survey consisted of seismic reflection, refraction, and guided-wave data along a 60-m-long profile. To acquire the reflection and refraction data we co-located shots and geophones, spaced every meter along the profile. We used 59 SercelTM L40A, P-wave (40-Hz vertical-component) geophones (sensitivity of 22.34 volts/meter/second) to record 59 P-wave shots and 59 SercelTM L28-LBH, S-wave (4.5-Hz horizontal-component) geophones (sensitivity of 31.3 volts/meter/second)to record 59 S-wave shots. We generated P-wave data using a charge from a Betsy SeisgunTM, with the charge placed approximately 0.4 meters (16 inches) beneath the ground surface. The charge consisted of an 8-gauge, 400-grain, blank shotgun shell. S-wave sources were generated by horizontally striking an aluminum block with a 3.5-kg sledgehammer. We acquired fault-zone-guided-wave data using approximately one pound of explosives within a mapped trace of the San Andreas Fault, approximately 1.74 km NNW of the recording arrays. The explosives were placed in a 5-cm (2 inch) diameter borehole approximately 3-meter (10 feet) deep. All data were recorded using a 60-channel Geometrics Stratavisor NX-60TM seismograph with a 24-bit analog-to-digital converter and a roll-along descaling factor, and the output data are in SEG-Y format (Barry et al, 1975). Each in-line shot was recorded for two seconds, with data recording starting 100 ms before the actual time of the shot. Data were recorded at a sampling rate of 0.5 ms, or 2000 samples per second. This report provides the metadata needed to analyze the seismic data. References Barry, K.M., Cavers, D.A. and Kneale, C.W., 1975, Recommended standards for digital tape formats: Geophysics, vol. 40, no. 2, p. 344-352. Schussler, H., 1906, The Water Supply of San Francisco, California, Before, During, and After the Earthquake of April 18, 1906 and the Subsequent Conflagration: Martin B. Brown Press, New York, 103 pp.

In June of 2011, the U.S. Geological Survey acquired high-resolution P- and S-wave seismic data across the mapped (Schussler, 1906) trace of the San Andreas Fault zone at San Andreas Lake in unincorporated San Mateo County, California. Our seismic survey consisted of seismic reflection, refraction, and guided-wave data along a 60-m-long profile. To acquire the reflection and refraction data we co-located shots and geophones, spaced every meter along the profile. We used 59 SercelTM L40A, P-wave (40-Hz vertical-component) geophones (sensitivity of 22.34 volts/meter/second) to record 59 P-wave shots and 59 SercelTM L28-LBH, S-wave (4.5-Hz horizontal-component) geophones (sensitivity of 31.3 volts/meter/second)to record 59 S-wave shots. We generated P-wave data using a charge from a Betsy SeisgunTM, with the charge placed approximately 0.4 meters (16 inches) beneath the ground surface. The charge consisted of an 8-gauge, 400-grain, blank shotgun shell. S-wave sources were generated by horizontally striking an aluminum block with a 3.5-kg sledgehammer. We acquired fault-zone-guided-wave data using approximately one pound of explosives within a mapped trace of the San Andreas Fault, approximately 1.74 km NNW of the recording arrays. The explosives were placed in a 5-cm (2 inch) diameter borehole approximately 3-meter (10 feet) deep. All data were recorded using a 60-channel Geometrics Stratavisor NX-60TM seismograph with a 24-bit analog-to-digital converter and a roll-along descaling factor, and the output data are in SEG-Y format (Barry et al, 1975). Each in-line shot was recorded for two seconds, with data recording starting 100 ms before the actual time of the shot. Data were recorded at a sampling rate of 0.5 ms, or 2000 samples per second. This report provides the metadata needed to analyze the seismic data. References Barry, K.M., Cavers, D.A. and Kneale, C.W., 1975, Recommended standards for digital tape formats: Geophysics, vol. 40, no. 2, p. 344-352. Schussler, H., 1906, The Water Supply of San Francisco, California, Before, During, and After the Earthquake of April 18, 1906 and the Subsequent Conflagration: Martin B. Brown Press, New York, 103 pp.